JPH0446434Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Industrial application field) This invention is particularly suitable for use in concrete structures such as high-rise buildings, underground structures, and marine structures, where it is difficult to tension tension members from the outside. This article relates to a curb air (tensioning aid device) for prestressed concrete that is effectively applied.

(Prior art) As a method of tensioning the tendons of prestressed concrete, when both ends of a concrete structure are open, there is a method of applying tension to the tendons using a tensioning device from both sides of the exterior of the structure. It has been adopted. However, this method cannot be adopted if both ends of the structure are not open, so for example, as shown in FIG. Then, the end of the tensioning material 70 is pulled out into this recess 102, and the tensioning device 100 is pulled out.
is inserted, tension is applied to one end of the tension material 70, and the tension material 70 is fixed by the fixing device 111.

In this method, since the fixing device 111 is disposed obliquely with respect to the lower side member of the concrete structure 101, the fixing device 111 is arranged in the axial direction (the first
A compressive force (reaction force of the tensioning force of the tension member 70) acts in a direction inclined with respect to the horizontal direction (left and right direction in Figure 0), and a component of this force in a direction perpendicular to the axial direction of the lower side member is generated as a component of this force. The disadvantage is that the dimensions of the components must be increased to withstand this force.

Further, as shown in FIG. 11, a curved tension assist device (curved air) 105 is inserted into a recess 104 formed in the concrete structure 101, and the tension device 100 applies tension force in the axial direction to the tendon material 70. Methods have also been proposed, but in the conventional method using curved air, there is no means to press the wedge in a tensioned state during fixation after tensioning, so a loss of tension force may occur due to the movement of the wedge. Inevitable.

(Purpose of the invention) This invention was made to eliminate these conventional drawbacks, and was able to apply tension inside a concrete structure while reducing the loss of tension that occurs during anchorage. The present invention provides curved air for prestressed concrete.

(Structure of the device) This device has a cylindrical main body formed with a recess curved in the length direction, and a cylindrical body that is inserted into the curved portion of the longitudinally intermediate portion of the recess so as to form both inner walls of the recess. a first slide plate inserted into the recess facing both lengthwise ends of the slide plate;
It has a pressing member and a second pressing member, and a recess through which the tension material passes is formed continuously in the length direction inside the slide plate, the first pressing member, and the second pressing member, and the main body is curved. In the recessed portion, arcuate surfaces are formed opposite to each other on the curvature center side of the curved portion and the opposite side thereof, and the slide plate is fitted so as to be movable in the length direction along both of the arcuate surfaces, The first pressing member is arranged so as to face the tensioning device disposed at one end of the main body, the second pressing member is arranged so as to face the fixing device attached to the other end of the main body, and the first The pressing member and the second pressing member are respectively arranged so as to be movable in the length direction together with the slide plate.

In the above configuration, it is possible to apply tension to the tendons inside the concrete structure by using curb air, and when applying tension to the tendons, the wedges attached to the fixing device are By pressing through the two pressing members, it is possible to press the wedge in the tensioned state of the tendon, thereby minimizing the loss of tensioning force. Furthermore, only an axial compressive force can be applied to the concrete member via the fixing device disposed at the tip of the curb air.

(Example) In Figures 1 to 4, the curved air body 1
is formed into a cylindrical body with a recess 12 curved in the length direction, and the recess 12 is open downward and has a substantially U-shaped cross section.
A flange 11 is formed at one end of the main body 1, and the tensioning device 7 comes into contact with the flange 11, and a handle 13 for carrying is attached to the upper outer side of the main body 1. A curved portion is formed in the longitudinally intermediate portion of the recess 12, and a pair of slide plates 2 are inserted into the curved portion facing each other so as to form both inner walls of the recess.

A saddle 3 is fitted into the center of the curvature of the curved portion of the slide plate 2 and fixed with a bolt (not shown), and the contact surface between the saddle 3 and the slide plate 2 is a curved surface with a constant curvature curved in the length direction. It is formed. Further, on the side opposite to the center of curvature of the slide plate 2, a support plate (plunger guide) 4 is fixedly attached to the main body 1 with bolts, and the contact surface between the support plate 4 and the slide plate 2 is also the curved surface. It is formed into a curved surface with a constant curvature in the length direction with the same center of curvature. In addition, a stepped portion is formed on the abutting surfaces of the slide plate 2, the saddle 3, and the support plate 4, so that the slide plate 3 is configured not to come off inward. The slide plate 2 is configured to be movable in the length direction between the saddle 3 and the support plate 4.

A first pressing member 5 is inserted into the recess 12 facing one longitudinal end of the slide plate 2, and a second pressing member 6 is inserted into the other end. As shown in FIG. 4, the first pressing member 5 has a substantially U-shaped cross section, and a fixing bolt 50 is attached to a portion of the first pressing member 5. The second pressing member 6 also has a similar shape, only the length is the same as that of the first pressing member 6.
It is formed shorter than the pressing member 5.

The first pressing member 5 and the second pressing member 6 are attached to the main body 1 by the bolts 5, and are configured to be movable in the length direction as the slide plate 2 moves.

Recesses 51 and 61 through which the tension material 70 passes are formed inside the first pressing member 5 and the second pressing member 6, respectively, and tension is formed inside the recesses 51 and 61 and the saddle 3 and both slide plates 2. The material 70 is movably inserted.

Next, the operation of this device will be explained. The anchoring device 9 is installed together with the wedge 8 in a recess 10 formed in the middle of the concrete structure, and the main body 1 of the curb air is installed so that its end is in contact with the anchoring device 9, and the tendon 70 is buried in the structure. wedge 8
Then, it passes through the main body 1 and leads to the tensioning device 7 on the other end side. At this time, one end of the slide plate 2 protrudes from the end of the saddle 3 and is in contact with the end surface of the first pressing member 5, and the other end of the slide plate 2 is in contact with the end surface of the second pressing member 6. Keep it. When tensioning force is applied to the tensioning material 70 by the tensioning device 7, the tensioning material 70 is slid and pulled while being crimped to the saddle 3, and the wedge 8 is accordingly moved in the direction in which the tensioning force is applied. become.

The tension material 70 is attached to the saddle 3 as shown in FIG.
Moreover, since the saddle 3 is recessed in its center, the tension material 70 is located at the center in the width direction of the saddle 3, and when tension is applied, the tension material 70 is attached to both sides. Do not touch the slide plate 2. Therefore, even when tension is applied, the slide plate 2 can be easily moved in its length direction.

After applying a predetermined tension force, when the first pressing member 5 is pressed by the tensioning device 7 in order to press fit (lock off) the wedge 8, the first pressing member 5 presses and moves the slide plate 2, and the slide plate 2 is moved. Push the wedge 8 through the second pressing member 6 at the other end of the plate 2, and press the wedge 8 in the fixing device 9 as shown in FIG.
The tension members 70 are clamped and fixed. Therefore, if the tensioning force by the tensioning device 7 is released in this state, the tensioning material 70 will be fixed by the fixing device 9 with a slight loss of tension.

Note that when the above device is used repeatedly, the saddle 3 will wear out due to friction with the PC steel material, but since the saddle 3 is detachably attached to the main body 1, only the saddle 3 needs to be replaced.

Examples of methods for applying the above-mentioned tension work are shown in FIGS. 6 to 9. In the example shown in FIG. 6, a curved air is inserted into a recess 10 formed in the middle of a concrete structure 101, and while one of the tendons 70 taken out from both sides of the recess 10 is fixed, tension is applied to the other tendon 70. By applying this, tension force is applied to both tension members 70 at the same time.

In the example shown in FIG. 7, a recess 10 is formed in a part of the concrete structure 106 such as the inner wall of a tunnel, a curved air is inserted into the recess 10, and tension is applied to the entire length of the tendon 70 by the tensioning device 7 in the same manner as described above. I try to add

The example in FIG. 8 shows a case where tension force is applied to a structure 107 such as a beam or slab of a building,
A recess 10 is formed in a part of the structure 107, a curved air is inserted into the recess 10, and tensioning force is applied to both ends of the tension material 70 by the tensioning device 7 in the same manner as described above.

In the example of FIG.
The tension member 70 is pulled to the end of the structure 108, and the tension member 70 is pulled out to the end of the structure 108 and the obstacle 10 is connected to the end.
A curved air is inserted between the tension member 9 and the tension member 70 to apply tension to the tension member 70.

In each of the above embodiments, the tensioning device 7 applies tension in the axial direction to the tendon material 70, and the fixing device applies only axial compressive force to the concrete member. That's what I do.

(Effects of the invention) As explained above, this invention can apply tension to tendons inside a concrete structure by using curb air.
Furthermore, when applying tension to the tension material, by pressing the wedge attached to the fixing device via the first and second pressing members, the wedge can be pressed while the tension material is in tension. Thus, loss of tension can be minimized. Furthermore, by using the curb air of this invention, only axial compressive force can be applied to the concrete member via the fixing device disposed at the tip of the curb air.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing an embodiment of this invention, Figure 2 is a sectional view showing an embodiment of this invention.
The figure is a right side view, FIG. 3 is a cross-sectional view taken along the line -- in FIG. 1, FIG. 4 is a perspective view of the first pressing member, and FIG. FIGS. 6 to 9 are schematic cross-sectional views showing examples of application of this invention to concrete structures, and FIGS. 10 and 11 are cross-sectional views for explaining the prior art, respectively. 1... Curb bench air body, 2... Slide plate,
3... Saddle, 4... Support plate, 5... First pressing member, 6... Second pressing member, 7... Tensioning device, 8...
...Wedge, 9... Fixing device.

Claims (1)

[Scope of utility model registration request] A cylindrical body formed with a longitudinally curved recess, a slide plate inserted into the longitudinally intermediate curved part of the recess so as to form both inner walls of the recess, and this slide plate. has a first pressing member and a second pressing member inserted into the recess so as to face both longitudinal ends of the sliding plate and the first pressing member.
A concave portion through which the tension material passes is formed continuously in the length direction inside the pressing member and the second pressing member, and the curved concave portion of the main body has a curvature center side of the curved portion and a side facing opposite thereto. An arcuate surface is formed, and the slide plate is fitted so as to be movable in the length direction along both arcuate surfaces, and the first pressing member is attached to a tensioning device disposed at one end of the main body. The second pressing member is arranged to face the fixing device attached to the other end of the main body, and the first pressing member and the second pressing member each move in the length direction together with the slide plate. Curved air for prestressed concrete, characterized in that it can be placed.